Quantitative determination of toxic mono- and non-ortho polychlorinated biphenyls in cod liver oil after selective liquid chromatographic separation

Hydrodebromination of decabromodiphenyl ether (BDE-209) in cooking experiments with salmon fillet

Polybrominated diphenyl ethers (PBDEs) are environmental contaminants regularly detected in biota and food. Seafood has been identified as the major dietary source for human uptake. Fish is predominantly consumed after cooking, and this process may alter the actual human intake of contaminants. This study thus aimed to investigate the fate of PBDEs in this cooking process. Heating of fish fortified with 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) at typical cooking conditions (200 °C, in plant oil) resulted in a decrease of its concentration in favor of the formation of lower brominated congeners. After 15 min, ∼25% of BDE-209 was transformed into nona- to octabrominated congeners. The major transformation route was BDE-209 → BDE-206 → BDE-196 and BDE-199. Low amounts of heptabrominated congeners as well as one hexabromodibenzofuran and a heptabromodibenzofuran isomer were also detected. However, penta- and tetrabrominated diphenyl ethers were not observed, and heating of BDE-47 did not produce new transformation products.

Combined microwave-assisted extraction and gel permeation chromatography for the determination of chlorinated hydrocarbons in seal blubber and cod livers

A fast and effective sample clean-up procedure for the quantitation of chlorinated hydrocarbons in seal blubber and cod livers is presented. Lipophilic sample ingredients are extracted by application of microwave energy. Microwave-assisted extraction (MAE) was performed with ethyl acetate and cyclohexane as solvent. Without exchange of the solvent, the organochlorine compounds are separated from matrix coextractives by gel permeation chromatography. Traces of matrix remainders were separated on deactivated silica prior to GC/ECD analysis. In this study we focused on quantification of PCB 153, PCB 138, PCB 180, HCB, and p,p'-DDE. In seal blubber, the recovery rates for these organochlorines were > 90% for the complete sample clean-up procedure. The standard deviation of the overall-method was within 5%. MAE of cod livers required softer conditions. After optimization of the MAE the organochlorine levels in cod liver were almost identical with those determined with another independent clean-up method.

Non-ortho PCB levels in various fish species from the east and west coast of Sweden

Non-ortho (coplanar) PCBs 77, 126 and 169 were determined in a number of fish species from the Swedish coastal environment, using either supercritical fluid extraction (SFE) or the traditional liquid/liquid extraction followed by HPLC separation on porous graphitic carbon (PGC) column prior to GC/MS analysis. While PCB 77 showed the highest concentration level, the TEQ value for PCB 126 was dominant in virtually all the samples analysed. The toxic equivalents, however, indicated some differences in analytical data between 1990 and 1992/93 but these are not significant probably owing to the short period in between.

PCB/toxaphene group separation on silica prior to congener specific determination of toxaphene residues in fish and other samples by GC/ECD

A precise quantification of toxaphene residues of environmental samples by gas chromatography/ electron capture detection (GC/ECD) requires the separation of the bulk of the polychlorinated biphenyls (PCBs) from the compounds of technical toxaphene (CTT) fraction. For this reason, a PCB/CTT group separation on silica was developed. B8-1413 (Parlar #26) and B7-515 (Parlar #32) eluted as first and last out of ten important CTT standards, and can be used to determine the elution volume of the CTT fraction on silica. GC/ECD quantification of CTTs was possible after separation of PCBs on 8.0 g activated silica eluted with 48 mL n-hexane followed by quantitative elution of CTTs with n-hexane/toluene (65:35; v/v). This method is a compromise between separation efficiency and consumption of material. Finally, eight CTTs were quantified in cod liver samples from Iceland and the Baltic Sea.